Balance Sheet Details (Details) - USD ($) $ in Millions	Oct. 27, 2018	Jul. 29, 2018	Jul. 28, 2018
Total cash, cash equivalents, and restricted cash
Cash and cash equivalents	$ 8,410		$ 8,934
Restricted cash included in other current assets	32		32
Restricted cash included in other assets	44		27
Total cash, cash equivalents, and restricted cash	8,486		8,993
Inventories:
Raw materials	421		423
Work in Process	0		0
Finished goods:
Deferred cost of sales and distributor inventory	116		443
Manufactured finished goods	758		689
Total finished goods	874		1,132
Service-related spares	248		258
Demonstration systems	29		33
Total	1,572	$ 1,544	1,846
Gross property and equipment:
Land, buildings, and building and leasehold improvements	4,707		4,710
Computer equipment and related software	1,037		1,085
Production, engineering, and other equipment	5,712		5,734
Operating lease assets	475		356
Furniture and fixtures	363		358
Total gross property and equipment	12,294		12,243
Less: accumulated depreciation and amortization	(9,338)		(9,237)
Total	2,956		3,006
Disaggregation of Revenue [Line Items]
Deferred revenue:	16,814		19,685
Current	9,637	9,788	11,490
Noncurrent	7,177	$ 7,114	8,195
Service
Disaggregation of Revenue [Line Items]
Deferred revenue:	11,062		11,431
Product
Disaggregation of Revenue [Line Items]
Deferred revenue:	$ 5,752		$ 8,254